SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac604b8d43b03646692408eb900c5fad87c19e1eedfc5925861f5d66aeafe419' 
  AND token = 'kgX15GLsCMVm1NQ1C0kVkS0SwfyZF1jglHc4VoASNyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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