SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ec9894e3fcc8911232f9aa26c76f92a3bc1948185751ebe58cb722d11654599' 
  AND token = 'bIpu35Rpv6oVEBkl+qiT+aMXkY8uISVL1bH1AYN/hmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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