SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64f4441752038759221acb3e03fd0ae7038dfae0360e1003ba2ce22bcd320ebd' 
  AND token = 'igwKpMYuI6X8Qf3h4rDsXCbtvhyp7uQk4Tn1ZpSg4BY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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