SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2db5f06a095a6bba0b58b6a4780621bcdd99429829e290f7ba586509dc19e8c7' 
  AND token = 'WKtlQ4+SnXl4mfaJGsOsWvVtSV8woN2pYHDkXFlV6yI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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