Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '4f90108844b4a23a892a4f2cc8bb55c3732c2d6f0e9756bdcbefebda2c8eb112' 
  AND token = 'WvtMFyH/HyglO3JCxoKQy3jZmBLEXnQ7R4TuvicOjrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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