SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3451917f87d6db34a1c5fc6da252c34aa0db62da9faf9985cd5c7780c2924912' 
  AND token = 'rqJa4lonpVczEHhaFiaeCWYXTd8xBU4KC9zm3vuJrJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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