SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94d57e1d8443c3e90cdad2831717ae6b9066afd1ee7cf1a5bf829ed3d5de02b5' 
  AND token = 'jTNCsGmfhf1i3s5uGBZJLJg6y0CVAwHXlbQSZ8tZxYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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