SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '45e2ea5497e3604887d2a0a98511860f9a2951e1aa3d267fb4890f898a963517' 
  AND token = 'Orcs3gQAnkMnqxmJh7nID2IHl0+k9f/9HZwtGiwIgTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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