SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '88301b6c095f908335d68e40badcaf23ffe724c6be8590430e0956c1c63d80d4' 
  AND token = 'oNkABCy3UrJoXbHBFYP/IAvuGij6P8hh/X6J6kkJiNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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