SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '354d4b38ed64792cf7f87bb711b4647daed5c6222fd80d6fcda41c27dc64c757' 
  AND token = 'zQ8ETZDw1FcVvOw5vXHiLc6lJ306V78DPx17f7oHP10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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