SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e218ad476224c6eb3739c377f95dd233b845a37d6c2b6c9408fe29bcfbc17320' 
  AND token = '0rH5snJFyHXBqV/UzffQxHw3KAXpNLinMjvOpHHb5ng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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