SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1a72c9bf2368b57d1b2ec951192b45c5b8295acbf326afbd76135eb4bfa3dd2' 
  AND token = 'YQDdkRLKZFAXU0e+cvpDDHuM78EaLC12F0NiQr7QHzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}