SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '444cdd95c449f197ec757ffefa7cd1814223501b1f8b0ca3d332b7865ef61529' 
  AND token = 'XhYj+vzQMcbbB6SS/4+1gy+JbCc8pqMCnFg4b5GPpdc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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