SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '094f744056416d2e2e13054ecac0321e8ef8dfb455e50231faac083fc231e55f' 
  AND token = 'idPTajB6IQMAlYeUSNgKA30fp9nDyhUzDx+uPK/kgJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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