SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2abca1daaaea00a44cfd24252dc523b5594d7cffd1851b97bce47e2fe89f181' 
  AND token = 'uQzB48jzRGk9a8LatrJjG0hTEtlzUxgvUY1rkvnHlZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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