SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c34e88f35ca66415047caa1bfb1e1f442c9c5a3474338e4a2147b91ffea79376' 
  AND token = 'qnzr09McDeNCiZffoMqZd7Q/SqsI/Ms9Aux6keb598c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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