SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2195d6d0c8821758ef3061231233774934c49a0151b3c472613eafe29a673d3' 
  AND token = '3WblbiBJbUTcTCrzy1NTLATlratstya1Q+bVIUZVW+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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