SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35d55f4e6424086aa0c7a01ec0f718a4cc9b3dad3d94d5387021313cc62457f6' 
  AND token = 'gufWTW5eGvrBF2VPDLUmju5srMC6IjaC43jvFRMixYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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