SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db26ccb8b62d06a5b49ad0496ffb5a552e2219af1c45ca00da350f4d195c464c' 
  AND token = 'm78U7/BCQLhFexiYDENDRjBZinRRz5leRXml+vloW9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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