SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4aedbdb5b5ddaf90498d37d49cc4746509f9c3ede34642fbff094df742e4fadc' 
  AND token = 'XjehmSz9qqCUOiLuIXzorRKKpjX6grJ6Myxy9zvSeJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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