SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '935e8709168f1f0d902c1874eb80d9861075982c7a4e3097b38bcf8fd13cc32c' 
  AND token = 'E/1LwnJw0QohKXRnaPIJEiUJjWZgJg8pluYVyFxsIJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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