SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41048064593136f49efa9a5c5f8b9e47d508a759c92eba1040b351f9cda5c706' 
  AND token = 'mYyWFmHnHMF2GKULZKHzihdIBjWKlxVDGEOJZj1TQmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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