SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82579f00565b12c9b3317b6d8cf2796bbd910af0d3ffc2bb0257e53b44c1fa22' 
  AND token = 'DNA7RK/kDwRsCIoofzXl5AKyxXalMhvCrBVVlRv1UdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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