SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46edf80cb9379865a05b42c3b8018ab8a25dc1c07d1bb68c527a0625fb660f14' 
  AND token = 'G3GnrCG4EgdtCbpln3ESoTD5fUzPoRrdi1nMe6siHNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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