SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4b26f069123e756dd9a4e92bea208b558b65d5a5b38b354129dfb3c806ef1865' 
  AND token = '7vjOJNMLP5zkfVnqG33bvvDJq1xx4aAwqAumP+2+U6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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