SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5355a4f2fb18e1aff75747cc7271d1857352784d1c0dd7dfe9ca04adbe88e961' 
  AND token = 'LqLTgx4i5lBdMx2hvzKEXtOsYvf15iowhoO+NZa6FCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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