SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25da16020d5dc50fbe503b9dc79751c6eeea7bc6377ad89b93cddcabbb275682' 
  AND token = '4uv9qiq3RWb3Zj7YyqoShO03mIbYMMG4bhlyFvLAmF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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