SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdad651c0c7444f782a7850a573f23790b1e226b4fab20138bf00f12f80aabc8' 
  AND token = 'vs4lcdDLHHBqaMPvO+rqrMMSqiRDbEXCZE/7IgyvJwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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