SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4783693a7c387e22457f83fc254de4fda5b0a1939a6a0365d949dd61254e0e5e' 
  AND token = 'PZNsPbStLHup78TC/YcvHg/DmtLfhi16esB6hECz2Wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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