SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea334920b72d9e3f62cbd352551a58129617e8a4ddc56cc5c117cb8391e41bdb' 
  AND token = 'qaWZTEGtjaau+UNKmHO7hLeGLHPCvNl/E+HwH2iaNuo=' 
  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"
    }
  }
}