Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e9cc199a1bf1a4791d2f9983be9ac45972f6302e7f8ddda8f3a8583bf60de377' 
  AND token = '50p+lBWSXp2f8W85dy9AT3XBAe4k7Z+dKUOHDu/OQ/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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