SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40c00493def6dde5d4f6d9128a6c7e58055efc13f7e5ee629f4854a730567353' 
  AND token = 'M7TzYkUtP4flTzUz6EckSrX/BfAcmHE7RHtw1FVO8vI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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