SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fbe9d185965fea76328fa71506b33ccb6c3184188e34d3a253e19bdc2c39705' 
  AND token = 'P4zsjZX7BiT/lQc9m3ohk+l/k85MbcQB3kGOaHV0BY8=' 
  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"
    }
  }
}