SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b3ba1a57bd1075c1351831badafa1f1809e17bc32bff1a0e3906023abc5c611' 
  AND token = '7GjxKOKC05V9Q18b8U21LYD049OoFNStoGqk2KB6IKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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