SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '332b5e6f20eac3ee4d435d2167cd5cfc1314ea9347936cc1fe61e14b01b312ce' 
  AND token = 'XfWalLcacWnvhasxoXnLcGByFdq8shxFwFLfvsyq4s8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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