SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c02e7defdefce4e1b375d8baf2df1a1054a2a1dc9af65311930c896a8571c5f8' 
  AND token = 'EfTgpHkMXQ54pdWeNqs0b1saAbMHG4VmcTfnN4LktuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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