SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '48f53b2cdaf7f44118ca38283043fbebde6a61fd61e2e0fa6e972ea4ccdf1f75' 
  AND token = 'uj46PFuZ/0On5X4820Ae8cxFpeUNZ4nWyLRSyN3AVzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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