SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9569cd9287236caa1fc992b6461a20a9898d9ff3c6a6404291f2081138850bc' 
  AND token = 'wq8pBzIzFmIVM1i9LjHZgRiGm74RgwdyUGIcuPQf8SE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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