SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14b9bda87222b47d8a7f8343662f0f91c430c74a4d076124e7568ce9d63991bb' 
  AND token = 'FdMSfqAyrp4S8wdSQzGQCOYOoqjRs3tG+PdnQhJGmqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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