SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e49483c4c312fa07d71173b74ef0ee275d838fe61a994d34cab167efe74e46a' 
  AND token = 'e/o9uKdp2973QdKUaAiqh3FTk4p/C9fmRfIcIgGehpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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