SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7f9379d02bc70ee3188e47cdc4523a2fa4235e354794a3df876d17fb2f9d3eb' 
  AND token = '5y5tATNf6Y5Y/wd0Wtv6K0JfDpn3J5RXbjoYqwwLeNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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