SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b9867392aee5385a1a9f1acc385e22d93a8ecafbf9dfab8e59d598f07cf1ffc1' 
  AND token = '8fSTkqmDffVbOc3pj0RyS8GwBufnNRUCRRYpeWVtC6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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