SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5dbd4cd0dc98b9c86e63d1f46d07481adbb19766c73d5d70b7a1bd1b2c23ed1' 
  AND token = '6b9FPPoyHhYfaPYCogCN1/iNc1TJPZ1S+W9PIJwrpXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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