SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd58d868bd9345a940192038b41f3e7a7fe0bb46e5c09ba8e31c831294ba9fb6c' 
  AND token = 'K18eB2KpVNb+9uwdb/k2XmY0GjLztzQzxR9q9BLjvPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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