SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9d03501d47d7e650968cf254b9d067a6d690794e129a0e4a4aa8cb485aeaa33' 
  AND token = 'hfrB8IyjTwPVErxiceSizEBAM8DaoIeEPepFUJVpPpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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