SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e777cc829816289da50f4fa775649206d673a5361fc58e34d52dbd40cc45061' 
  AND token = 'qle95J+ZUqvwKAaV7PScWomZqlzE2LFeWjaHk+rH/UY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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