SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b359058287b048b1a79ecf61e1bee1781109d4cf52b28e8c4286f7133de8d926' 
  AND token = 'SjONKCz9sUYNTY9IjvgIzzF4A5owugFMZAR1q6XYyDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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