SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '48a79855ef6033c260b49b0bcbe32b888eae4847f442b3d661074cba1b7389dd' 
  AND token = 'Cqps8Wqz6Hp0pNPYcU3K4oekiI58LIkvb2KCTk/qfpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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