SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a601bc01e35928a738cddddb4e966ee30c05504b7f2b1f0f64b1c8918cc69afe' 
  AND token = 'dHKNmFn+brJ+LROwAQFLCwq7x0uPE3n7GHZhWFSDxKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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