SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9a4e2609faeea7729095d9b94d046def731401ac75d32a7eb556ad33773d8e93' 
  AND token = '82pB/Eel+KHzB8I3yjEdfb7C2tDZYL/kzJWGNIfXVxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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