SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f52d6d38cf2be96845afc08818fdd1ccc2fdd1b463c6e2c755d0b61b27a6231c' 
  AND token = 'yERcUTR0ulwZsaZV326SL7cOyeqJILnWXirxWypv5VM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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