SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd3557de4714ca7881019d6b6f7702ab45171bc3ad1cd6848e7d828503a227f2' 
  AND token = 'YBm3IsJ7pa1dd+c19KpjopsngYZ6N8uBvVuJxeOmWhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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