SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23841d53c884c4f545fbe6bbd7c0bca1c8ecd18100ccc402602738673509d473' 
  AND token = '1ej6r99RxFNXZ2h5EeqcGYPR1ZzmGPVQVwn/nHiO3nY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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