SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f494f1ffde1f2e1c8126dae73900f84e656cf10d88220a42bca94f3019760f1b' 
  AND token = 'G4qrs4GmZKhfOgLzIP8E3wrnHlvkTM5EEcKhyCvzMkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}