SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56a87827718cfe0a06909eda2687be29ad0bd58f018c453112beaeaf6a35fbd9' 
  AND token = 'HLCzj9H5pgrT4m1G13w/ExGw3D2bpZxcUjMoKBtXW/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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