SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e5d8b40832011f88ba02818b2ddf36d595b5e9c6dd629b017a9f010785c25c4' 
  AND token = 'bJWI5X4HLWM778SziBfTped7ePqor6sLmSVAFHotffA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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