SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b88d73b235097724eb46064964e11c481eeb85353b38097bb73cd893009d43f1' 
  AND token = 'G6RnMA7dKjvmnpGxiFK0DU2KxBEzQBq9kWZ6rHx+u2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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