Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd879b10751d50c0539c035dd44ff2cb83924a016eaace45aecf9c9ceaab5754' 
  AND token = 'gl2xS8JVBmdDg3YcjTPpSt84JLCzL6PoEeWkO0ai/6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}