SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93b28ea2ca4eb45f9979837660dc7cf0faf6b36067a77f4a7383af46cd5f6c67' 
  AND token = 'ZUsZ9wLvqx4qTrFYev1GdxCSn0TlyAnVRrfofWp8Ijo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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