SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2e18185c532a675c788f99b8968d73c0a52206b243119ef701ca0fa0645bbfa' 
  AND token = 'NJ6un1G3TBwbzLyTfvwS/jhx8wwZqekdOOvbIEIDZQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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