SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f482083a1cfe4ba775bb0829f20415582468920fc7755ba2625044967fec4bbd' 
  AND token = 'BaKmHU/6teGwNt4LLdb81PwtyyYfT9cd+Je8ZnFIbgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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