SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dba1576b3869473140253aee74ba48d41ad6773bef606993904a0b21f840aab' 
  AND token = 'Eb0Ma4osFKUoSzY5dNQ4aganE+f3q+bO+4gk2t8eu2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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