SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5a7cf010f68d097a43bd10ab4abd23841962b5a1cd6873a2bce8a9a3a06b885' 
  AND token = 'w3WqpkBdpzFJXtPMS/e4JJsshlUZa8BSMtTh7nHx094=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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