SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f262895f935a084fff0e051019f315569395ce729d61c2b2a0fc4bb8c85cef3' 
  AND token = 'JvQsN84Zv0b5hkb1P6QQYEuBgdHRR5SiIxLAGzKswoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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