SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e82d900aa05f99bc2462dc0b33be644657fd0fe44c559fbddb7dd631938a1fc6' 
  AND token = 'luvhNlbVNNkwsGsThjNKLpTVgfXjvKnMP5hgTO2OgUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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