SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ef51d4923c255a51a9851a2271a5f5fe85074b0bc7e36246727795f90a8e1b8a' 
  AND token = 'zWHk4Y7RiJdwuTygTF/WonHuFRtZmqu9xwq1gpQ9fsY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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