SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e86b259c6aa10cfd7f165194d4d8213b5f88fe819d9b9111782a437a25f02e03' 
  AND token = 'kzL/p91t/pvNKzhh6TBrvczNZpiHiJlq4GPd01QEFN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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