SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd29d3ac4d9689f6def313fe3afa70e6ea94ac2ba4f547c47586284f1f42b0ac' 
  AND token = 'ZrFgGMWMqnKCl0WkZSF5V6EGVXgo+5hNK2YbvOMDsFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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