SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '2eb375a89d19f81edf69cd46d96e39a69facbcd6ca8c7b7b6a63a9054134a51e' 
  AND token = 'eFT4Nujku9EUIymEga0mqR/gCeFPco6hTqRUw4a1Z4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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