SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '914568c1f6632a616b42f0ffed7a4799b86b5f8de109223d06d912ee7cc70677' 
  AND token = 'XLenFkklnXFOXT+jFcgGUqQ71hCN74s1Un252a/WzoQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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