SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7364aedac6199745422190b1e651a58c2aa0782b07c19d07f315a5d1390b9d4' 
  AND token = 'arbgB+uc9h9bzFWcJmI5UvABMrDXr0Htx9rmDBoHRcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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