SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fec7341fc754797651c3ec25c34d6f66bb852a0f173765594aeec82e97a2ce36' 
  AND token = 'blZpPKlvABfvvXd2EGbFlq5qQRHH+n63YBiAhA+XHNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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