SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '656ab7fb2e1d541e913c0f412115b20094828ce9ff89cd6353fe15570b893fda' 
  AND token = 'bG1IeCGq6OjsjHJ9dLtoDICrYYcH6lPhsa9QTttMVds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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