SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3659c528625663ecdea0762ac007e48ab9b46545bb44f3c8d01758dbe9b8a2f4' 
  AND token = 'XG1sbREwp5WtBygUhVryLddDES/dTNvqSLFw68JpjOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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