SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02c3db4665d460a491f6c1eabe97438dab3c6df4603d47e308b63157ffc03360' 
  AND token = '2hHbVZo5uxxkQkJ9RVH5wcqPDsjliAJzL0/w5oPC510=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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