SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a63cac07b44270e7d4e79dad59063eed9b6b518d282b2f37adbe59ffccb6061' 
  AND token = 'VZuYzigyFFwYVA4EkOPLBFwE4++dJxzyzvaxRQUwmyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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