SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9068760f0704631adc31927b148f896ec65d30865b803b7b82410b6e24d48e56' 
  AND token = 'w8veuQVrmKn2E0OdY1EA+Nst18oT2A+aiSlX0naYm2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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