SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7cee896d251bf2642973ca680c073afe3986f007a3bf802696807f3acb5e589' 
  AND token = 'UwPa4+lrLg/sLDvQ1iU2MQX3MOUskHjRB6R0FswWKbA=' 
  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"
    }
  }
}