SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8874bb1ef24246b61365a66a57d4792c233e379115856af032cd841493da36e1' 
  AND token = 'aIqJUMbdBIljOFyaqy7LJQUD6uf8rXX4NOdSOyM2608=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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