SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cd91fb30903a9802ece84dcf38823d7c458c94ccc3635dcb3f31fbf7b91e522' 
  AND token = 'JtRkB6A6aQM/9VCjWwPKrTKfcEsryhyLWY5jWE8PBMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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