SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4faf12f1c38ccce040e39fe11d500137fe2c09da51cfb4fbcb6d506cc09fda1c' 
  AND token = 'XFSpMnaApwusG4ftCgr7E8FRYNUyNzNmOxT6DwSAink=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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