SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92eba48ff0664b88f72a4cb4c8f6ff3078bb331421722d995bd27c2078841ab5' 
  AND token = 'HwUTNv7hFSB6hzPf7/IDpj+Pd4tDCzhTEkGJ13NGjYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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