SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baecab6480f8b8b5e60d9c9176c89d1f991c0da4a849e1d4cf6acf016799801c' 
  AND token = 'GYV2BlQznVhlFrnP90uHaQWtppzrUIx+DAAXw+wdf34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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