SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '041e0950213e380232339ed8ad881ead430f1f9e3f352f3f396d103ed2634eab' 
  AND token = '6TirltzlCyzHajVVWjTtPuMNHKbmOnNhBzF0j8hXHmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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