SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c60d06e8aa0faf7b608cb892405f99ab547168cffacabd197062cd8365a279fc' 
  AND token = 'uF6fE5SBeFt2tY0r6cHUqOXz2jL2RgyxiCgc+ERc+mY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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