SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d3172237542b30b85782de15a8746f8c4fa0a1d7a60965baeb78494f643a464' 
  AND token = 'vuC/+JkZ3ri5fJkLCShIEZ+i02Tsv1QuRhe+GHmYOdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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