SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38b09a2dbca5248097a1826cca4827dcc370b1cc30ac44b010d82193ea65cd23' 
  AND token = 'Oy3G23PZfDlqXRM71CFie7VGZwGn8jlujQV8dourfNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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