SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '102081b2c5a5f20d94c941cb6fd42df94fba56f2aaa0d4efd4fb2ad4629bbcae' 
  AND token = 'johrhWuT+ijx1qOic6OJgElasn9q4w3kAw+6W3ibQYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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