SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfa33351930fcc3445e7be40100b31e5bd3a627b0c5cd91783d9207adeae5575' 
  AND token = 'X7csK3f431EVQtvNrqXzys1rZl5wo2sHUiw90AUw6PU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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