SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0845c94974dd6e4afea9c04acbb14ce56dd6f253cdf326439fc57b213370f176' 
  AND token = 'BOxUN3KFJJVQoJ66vS6MUar5+KoFXA4iczlHtK7rGSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}