SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdde7202644f4f693ee479d4761f58c39bcd496f110f245c13d55ad2cba41829' 
  AND token = 'fsAiCWIixF/GnyhSNj/KsMiEUxsoSXzIBx90KLFsIb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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