SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97b14f21a582d5dde47db45df5e57a45efd478c74673da013e5245091fd828bc' 
  AND token = 'oa9cQUXgsXLi44JYvsFZRi4BwLadforPqXZe3i5nIIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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