SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4714f9e26d532bc28d6439ad2b950b8bac3a631df609e4931dac4344691716d2' 
  AND token = 'KVTPSMwq+CK68Qz6Om5BGyBOqZk9YMUi/rFpjoYUvyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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