SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8caf42ca0fba96f939d8b9f9c0fc074aca7586da3c381d47e1eac4a2b9a331d6' 
  AND token = '3qXRDOuq62I5h0PZhqNytaUkl2z+uuvWeDK0vxu4im0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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