SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bcdd1436a153ca6c0d312f6e23fffdab61ee98a260c857d1fb2a49b3fefb165' 
  AND token = 'Yc137v1MFmgYkQWMWm+wQZpLv6tv93r7PVK7wjHHFos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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