SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a381a18f853f13432b3148cbc740231d5dd31362da81bfae432a0da3d64ef1b' 
  AND token = 'O1we9dnZlgBfVxTCsCXUiCiO6IVJtDxn0+wFoPUbmjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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