SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a86b8a51da2e4bef2b12604bc6857de52d7853dbea5019c5e405e796bde7a624' 
  AND token = 'GSfylM8C+ofPCwIYtfnELXwTghxEOxmtIf/tiWM66FY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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