SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7037836d724b50c0dfa5d0dbbe98714f87ef5e3f64b7d4057ae541faefcda7c' 
  AND token = 'zoj7wmLPQhG3GDhFxNzkgB08nSQDfk4LqfGchBQKIgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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