SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2a276a1df856e9c3248aef514c77574080f18ceae7467f549144feb3c786502' 
  AND token = 'tCWM6Y9RwX/lwvksaFHqb8q1bjNGzET2tWK7PYqSPX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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