SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69fde1b9cc3faacfb4b372d08f0b7899067d197925cecf0ff381643cef00b338' 
  AND token = 'wIqaKe/1VojVlcVQozzjl+v+m93nhYhEFg6iUhgm5kA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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