SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e4d02123d188a8bada78810e9ef132b3b86f39a43baeed897b09ff5ea1c9845' 
  AND token = 'hUh0usgs3KRKNbrNuF1hbrjdCur5BTAHRFit/8ZA3yY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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