SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c1a91e141bc166c52769653dfcaefc628cd82e98f67a2d5c9df50d16a76e3162' 
  AND token = 'ygxFr2HrnD7SorSyWm5DdnXLXHJgNhKNa2pRYAkBk1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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