SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86bfec78cdffe6c876d746bf27153c8cc0ca4afa8c8b69b8886c95a616df3d43' 
  AND token = 'BCnaAshSaOIQ4uZrUVc4Fc9yjVtC/RGLB7mXXKE0qr0=' 
  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"
    }
  }
}