SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6e33356a1595df9fa4bf695213640680ad66714399ebf1c15b0dc4ef7359669' 
  AND token = 'Y+8SYuG9s3Gx1RghCVVAbDM1IAV1/D2Yr8P7A8mkPBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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